added mouse wheel support c++ and python. (fixed image draw when size mismatch, fixed enhanced window image out of window)

[mwindowshz]

added mouse wheel support.
but opening the commented theFlags int
void handleMouse(int theEvent, int theX, int theY, int theFlags, void* theData)
function.

how this update is good. tested this on windows. (cpp and python)
and in linux the python version. that mouse wheel event up and down was recorded.

in Enhanced window
there was a bug, EnhancedWindow draws image outside of window issue #95
EnhancedWindow draws image outside of window
added my fix commented line 74

//cvui::beginRow(frame, mX + std::lround(10*mFontScale/cvui::DEFAULT_FONT_SCALE), mY + std::lround(30*mFontScale/cvui::DEFAULT_FONT_SCALE), mWidth - scaledTitleHeight, mHeight - scaledTitleHeight);

Bug cvui:image() crash when size of image is larger from canvas issue #94
added if statment to solve the issue:

void image(cvui_block_t& theBlock, cv::Rect& theRect, cv::Mat& theImage) {
		if (theRect.x < 0 || theRect.y <0 ||theRect.x + theRect.width > theBlock.where.cols || theRect.y  + theRect.height > theBlock.where.rows)
			return;
		theImage.copyTo(theBlock.where(theRect));
	}

Please test my changes,
Hope these changes can be incorporated in your repository, and pip install versions of cvui

Thanks for your great work
M.

[Dovyski]

That's an awesome contribution, thank you very much!

[mwindowshz]

fixed compile problem. when opencv version is 2.4
added support for mouse double click